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| author | Steven Rostedt <rostedt@goodmis.org> | 2008-05-12 21:20:58 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2008-05-23 21:47:07 +0200 |
| commit | 2dc8f09571a61d9cb3dc47bba6608689dfe15d16 (patch) | |
| tree | 5f23089a821ecff3ae9c57206b10d911f67cd279 | |
| parent | 845279972f1736c3463c9cebd1bad92a0a347176 (diff) | |
ftrace: trace_pipe implement NONBLOCK
This patch implements "NONBLOCK" for trace_pipe. If the trace_pipe is opened
with O_NONBLOCK, then the trace_pipe read will not block when buffer is empty.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | kernel/trace/trace.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2af940433e9..3b4eaf36ed5 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2233,6 +2233,10 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, start = 0; while (trace_empty(iter)) { + + if ((filp->f_flags & O_NONBLOCK)) + return -EAGAIN; + /* * This is a make-shift waitqueue. The reason we don't use * an actual wait queue is because: |